astronomy test review

Foucault Pendulum

A freely swinging device whose apparent shift in swing direction provides direct evidence of Earth's rotation.

Coriolis Effect

The apparent deflection of moving air and water caused by Earth's rotation, deflecting pathways to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

Primary Cause of Earth's Seasons

The tilt of Earth's rotational axis at an angle of $23.5^\circ$ relative to its orbital plane combined with its revolution around the Sun.

Geocentric Model

An early celestial model proposing that Earth sits stationary at the center of the universe while all other bodies orbit around it.

Heliocentric Model

The astronomical model proposing that the Sun sits at the center while Earth and other planets orbit around it.

Kepler's First Law

The orbital path of each planet forms an ellipse with the Sun located at one of the two foci.

Kepler's Second Law

An imaginary line joining a planet and the Sun sweeps out equal areas during equal intervals of time, resulting in higher orbital speeds near perihelion.

Terrestrial Planets

Dense, rocky planets with solid surfaces positioned closest to the Sun: Mercury, Venus, Earth, and Mars.

Jovian Planets

Massive, low-density gas and ice giants situated in the outer solar system: Jupiter, Saturn, Uranus, and Neptune.

Spring Tide

An extreme tide featuring the greatest tidal range, occurring when the gravitational forces of the Sun and Moon align during new and full moon phases.

Neap Tide

A moderate tide featuring the lowest tidal range, occurring when the gravitational forces of the Sun and Moon act at right angles during first and third quarter moon phases.

Lunar Eclipse

An alignment occurring at full moon when Earth passes directly between the Sun and the Moon, casting an umbral shadow over the lunar surface.

Solar Eclipse

An alignment occurring at new moon when the Moon passes directly between the Sun and Earth, blocking sunlight from reaching Earth's surface.

Redshift

The lengthening of spectral wavelengths emitted by distant galaxies toward the red end of the spectrum, providing evidence that the universe is expanding.

Cosmic Microwave Background Radiation

Uniform, faint electromagnetic energy detected across all directions in space, serving as remnant thermal evidence of the Big Bang.

Nuclear Fusion

The stellar process where lighter hydrogen nuclei fuse under extreme heat and pressure to create helium, releasing radiant energy.